Thousands of satellites have been launched into earth orbit, with nearly 1,000 of them still active in providing valuable services such as military and intelligence data collection, global positioning, telecommunications, weather and climate monitoring, and so on. It can be important to know the actual location of a satellite at all times during its operational life from its launch until it either reenters the atmosphere or, in the case of a satellite in geostationary earth orbit (“GEO”), enters a graveyard orbit. When a satellite is launched, the satellite may initially enter low earth orbit (“LEO”). If low earth orbit is not its final orbit, the satellite will eventually fire its rockets to maneuver into its final orbit, which may be middle earth orbit (“MEO”) or geostationary earth orbit. Knowledge of the actual location can be used to help ensure that the satellite is moving to the correct orbit, stays in the correct orbit, has maneuvered correctly, and is working properly in general. For example, a satellite that may have been in the correct orbit and working properly for several years may stop communicating. Knowledge of the actual location would be useful in determining whether the satellite has stopped working but is in the correct orbit. If the actual location indicates that the satellite is in the correct orbit, then efforts can be undertaken to restore the satellite to proper working order. If, however, the actual location cannot be determined, then the satellite may have experienced a catastrophic event (e.g., collision with space junk) resulting in the breaking of the satellite into several large pieces (i.e., space junk), each of which poses of risk of colliding with other satellites.
Although a satellite that is working properly can send its actual location to ground control, once a satellite stops working properly, it may not be able to send its actual location. In such a case, an external tracking system is needed to track the actual location of the satellite or its pieces in the case of a catastrophic event. Such a satellite or its pieces are referred to as “target objects.” Although ground-based telescopes can be used to track some target objects, ground-based telescopes may not be particularly effective because of gaps in tracking coverage, high cost, poor atmospheric conditions (e.g., cloud cover), and so on. It would be desirable to have an external tracking system that could provide effectively track target objects at a reasonable cost.